KKR, Bain among bidders for Tyco's $1.6 bln S.Korea unit -sources

* S.Korea security systems unit worth around $1.6 bln -sources

* Blackstone (NYSE: BX - news) , Bain previously acquired similar security firms

* S.Korea has seen much private equity-backed M&A this year

By Stephen Aldred and Denny Thomas

HONG KONG, Dec 9 (Reuters) - KKR (Frankfurt: A1C10P - news) & Co LP and Bain Capital (Other OTC: CGHC - news) are among suitors which have placed initial bids for Tyco International Inc's South Korean security systems unit, a business valued at about $1.6 billion, people familiar with the matter said.

Billion-dollar buyouts are rare in Asia, but security companies, when they come up for sale, tend to attract much interest from private equity firms as they are valued for their stable revenues.

A sale of ADT Caps, would follow Bain's $3.4 billion purchase of European security firm Securitas Direct in 2011 and Blackstone Group's acquisition of U.S. firm Vivint Inc for more than $2 billion last year.

Other bidders for ADT Caps include CVC Capital Partners as well as Hong Kong-based Affinity Equity Partners and South Korea's MBK Partners, the sources said, declining to be identified as the process is confidential.

KKR, Bain, CVC (Taiwan OTC: 4744.TWO - news) and MBK declined to comment. Tyco and Affinity did not respond to emails seeking comment.

Morgan Stanley (Xetra: DWD.DE - news) is advising Tyco on the sale, the sources said. Morgan Stanley declined to comment.

Tyco, a provider of commercial fire and security systems, became a much smaller company after the diversified conglomerate Tyco International (NYSE: TYC - news) split up last year. Its North American home security arm, ADT, became a separate company and its former flow control unit merged with Pentair Ltd (NYSE: PNR - news) .

ADT Caps had earnings before interest, depreciation and amortization of $160 million as of the end of Sept. 2013. The business is expected to fetch around $1.6 billion, based on a ten times EBITDA multiple, the sources said.

That compares with valuations of around 8 times EBITDA for Securitas Direct and Vivint, they added.

Established in 1971, ADT Caps offers central monitoring, access control, video surveillance control and other integrated security services.

South Korea has also emerged as one of Asia's most active markets for leveraged buyouts this year as banks, attracted by the higher returns that leveraged buyouts bring, have become more willing to lend in a low-rate environment.

South Korea has captured 26.7 percent of market share for Asia, with $6.27 billion of private equity-backed M&A deals. That is ahead of Australia, and second only to China, which has a 35.4 pct market share.

The deals include MBK's agreement to buy ING Groep (NYSE: IDG - news) 's South Korean insurance unit for $1.65 billion.